Historically, blessed thistle was very popular in Medieval England, most likely due to the legend that King Charlemagne was visited by an angel that directed use of the herb to counter everything from headache and poor memory to the black plague and smallpox. This attribution, coupled with the fact that monastery monks were tasked with cultivating blessed thistle in quantity, is why the herb is also known as holy thistle and St. Benedict thistle.

The bitter, astringent qualities of blessed thistle are due to tannins and alkaloids, most notably a bitter compounds called cnicine. The herb is traditionally prepared as tea, tonic infusion or tincture. Blessed thistle is also made into herbal bitters and aperitif digestives. In fact, it is an ingredient in the classic angostura bitters formula.